Two-wheeled tractor



Jan. 27, 1953 A. s. LEIGHTON TWO-WHEELED TRACTOR 2 Sl-iEETS-SHEET 2Filed Sept. 27, 1947 4 INVENTOR.

. HR THUR 67L: [el /r0 H TTOR NE V5 Patented Jan. 27, i953 UNITED STATES'AT-ENT OFFICE "TWO-WHEELED TRACTOR 'Arthur S.;Leighton, Portland,:Maine Application 'Sep'teniher 27, IML'Serlial No; 7%;481

4 Claims.

My present-"invention relates to two-wheeled tractors and to theirconnection with a "towed unit.

{Two wheeled tractors 'have proved to-be of real value, particularlywhere relatively small areas are to be plowed orareunder-cultivation.There are, however, several objectionable-"features to them whichseriously limit their utility. h 'These objections are that such atractoris not sufficiently flexible in use to meetactual operat ingconditions which frequentlyrequire either a reverse drive or" a changenfits speed regardless of the-particular use to whichthe tractor is beingput. WhiIe'SuCh tractorsare adapted to tow a wide varietyofunits-such'units' are commonly a-plow,-harrow,-orcriltivator.

-When such a tractor-is usedwith a cultivator, for example-"considerabledifficulty-exists both' as to the control of the cultivator and theea-se'with which such control may be'effected. Where the rows to becultivated are not perfectly straight, it is necessary for the operatorto so steer-the tractor as to-maintain the cultivator in desiredrelation to the plants. "With the usual two wheeled tractor and theusu-al-connectionbetween it-and the cultivator orother tractor -unit,any shift in the directionof the tractors travel=-is attended by alateral shift of the unit at its pivotal connection to thedraw bar ofthe tractor. This has the disadvantage that substantialeffort is"required in steering and the undesirableconsequence; particularly incu-ltivating,-=of bringing the cultivator into contact with or too closeto the'plants.

-In-accordancewith my invention; I provide a two wheeled tractor, thedrive for-whichdncludes a transmission and *adifferential unit with thetransmission preferably-providing both a reverse drive-"and a pluralityof forward speeds. I'aocomplish this result 4 byproviding-a frame with Ia differential unit "supported between its-ends and having-its propellershaft rearwardly-disposed. The engine is *mountedadjacent the front-endofth'e frame'and its crankshaitis coupled to the drive shaft ofthetransmission by any suitable clutch. means such as a beltedconnection under the control of abelttightener; The transmission islocatedabove thediiferential unit and includes a 'rearwardly extendingdriven shaft which, adjacent the rear end-of the tractor, is connectedto the propeller shaft, "preferably by a vertically disposed geartrainproviding a suitable speed reduction between those two shafts.

"The frame. of my tractor includes at its rear a draw barto which thetrailer 'unit is'to be pivotally connected and upwardlyinclined-armsinterconnected by a transverse support-towhich is centrally-pivoted alever having a 'dep'ending arm to be pivotally-connected to the trailerun'it rearwardly of its pivoted connection .to 'the Ltractor. As aconsequence, I when the tractor sis steered as by swinging its rear endto one side $01 the other, thelever isro'cked because of itsconnectionwiththe unit. A h'andle -pivoted:.to each A arm and includes aihandle.por.tion.:and .:an end portion extendingforwardly .into the zone of thelever so that its end portionlmayibe:connected to the adjacent end-ofthe lever by' a link.

'ln accordance with mylinvention, theiend portions 01 the handles aresufficientlylonger than their "handle portions so'thatitii impossiblefor thecperatorto steer the tractor by pllShlIlgllOWIl onone handleportion and liftingithe .aoth'erras that mode of operation wouldLseriouslyinterfer-e with the extent'lto which the tractor could beturnedrelativetolits towed unitand would re-. quire substantial movementof the handlen portions .bec'ause of ithearequired leverage. gAs casoonsequence, my tractor may :be steered .by {the handlesonlyibyzswingingzthem laterally asza unit to one side or theother.."Suchmovement results, however, in .an equal but opposite .movementsofthe handles. so that they are conveniently repositioned for the operatorwhenever.phezchanges.Lthe direction of the tractorfsttravel.

In the accompanyin ;drawings,rI have shown an illustrative embodiment ofmy inventionfmm which .its several novel features .andadvantageswillbeoreadily apparent.

In the :drawings: Fig. 1 is a side view of.a.tractor'.in:accordancezvith my invention with .acu'ltivator connected lgig. :2 is a top planviewoftthetractorof Fig-kl, an

Figs. 3,4, and 5 are enlarged;sectionszalongithe lines 3434 1-3,=andi:55. respectively nfzzliig. Ll.

In theembodimen'tlof-rmy invention shown :in the -.drawings, .I have.indicatedthe frame-at :I fl havin a pair of spaced partitions: l-lsand:l-2. Between the partitions .H and vHZ, I -mount a transmission unit[35a substantial distance above the frame Ill.

' The transmission unit 1'3 maybeofant'edesired type and preferablyprovides a reverse drive asz-well as a. choice of forward speeds.-I-have;. indicated its drive shaft at I 4, its; driven shaft -at 1.5within the tubular .housingJfi, iandangear shift lever 1.1 extendingrearwardlyxof the; tractor to be conveniently. accessible -to v.the.zoperator,

3 The drive shaft l4, forwardly of the partition H, has a pulley l8 andfast on the rear end of the driven shaft and housed in the gear box [9is a gear 20.

Any suitable engine 2| is mounted on the frame In adjacent its frontend. Its crankshaft is indicated at 22 and fast on it is a pulley 23. Abelt 24 is trained over the pulleys l8 and 23 and to provide an easilyoperated and reliable clutch, I provide a belt tightener which consistsof a roller 25 rotatably mounted on a lever 26 pivoted as at 21 to thepartition II. The walls II and l2 have ears 28 and 29 having alinedapertures through which extends a shaft 36 having on its front end acrank 3| to which and to the lever 26 is pivotally connected 6. link 32,see Fig. 5. By rotating the shaft 36 in one direction or another, theroller 25 is carried into or out of a belt tightening position. In thebelt tightening position of the roller 25, the pivotal connectionbetween the link 32 and the crank 31 passes slightly beyond dead centerso that the pressure of the belt 24 against the roller 25 is ineffectiveto render the belt tightening means inoperative.

Secured to the rear end of the frame are a pair of spaced upwardlyinclined arms 33 interconnected adjacent their rear ends by an arcuatesupport 34 apertured to receive the shaft 35 of the operating crank 36which is located conveniently adjacent the operator. The end of theshaft 35 is shown as connected to the shaft 36 by a universal joint 31.

At 38, I have indicated generally a differential gear unit which may beof any desired type and to its axles are conventionally attached thewheels 39. The differential gear unit 38 is supported by the brace 46and by the tubular housing M for its propeller shaft 42 below thetransmission unit l3. One end of the propeller shaft 42 has a gear 43housed within the gear box [9. The gears 26 and 43 are preferablyinterconnected by a vertically arranged gear train effecting asubstantial speed reduction between the shafts l5 and 42. As may be mostclearly seen in Fig. 4, my gear train includes spur gears 44 and 45.While step gears may be used, I prefer to mount separately smaller gears46 and 4'! on the spindles 48 and 49 on which the gears 44 and 45,respectively, are mounted. The gear 44 meshes with the gear 20 while thegear 46 meshes'with the gear 45 and the gear 41 meshes with thepropeller shaft gear 42.

The frame ID has a draw bar 50 to which a cultivator, harrow, plow, orthe like may be pivotally connected. For convenience, I have indicated acultivator generally at 5|.

A lever 52 is pivotally mounted on the support 34 and includes adepending arm 53 to which is rigidly secured as by bolts 54 an extension55 pivotally connected as at 56 to the cross member 51 of the cultivator5| rearwardly of its connection to the draw bar. By this construction,when the tractor is steered by shifting its rear end to one side or theother, the lever 52 is rocked.

I provide a pair of handles generally indicated at 58, each of which ispivotally attached to one of the arms 33 as at 59 to establish arearwardly extending handle portion 68 and an end portion 6| extendingforwardly and connected to an adjacent end of the lever 52 by a link 62.In accordance with my invention, the end portions 6| are much longerthan the handle portions 60 so that insufiicient leverage exists toenable the operator to steer the tractor by pushing down on one han- 4dle portion and lifting up on the other as such a mode of operationwould require such substan tial movement of the handle portions to meetthe leverage requirements that it would be impractical to provide asteering range to meet typical operating conditions.

In accordance with my invention, steering is effected by the operatorswinging the handles 58 to one side or another. Such steering results inequal but opposite movement of the handle portions 60 repositioning themfor the convenience of the operator.

While I have added transmission and differential gear units, tractors inaccordance with my invention are suitably compact and have their weightproperly distributed relative to their wheels. At the same time, theyare well adapted to give efiicient and economical service which,combined with their adaptability and maneuverability, renders themadmirably adapted to meet a wide range of operating conditions.

What I therefore claim and desire to secure by Letters Patent is:

1. A two wheeled tractor comprising a frame, first and secondlongitudinally spaced, transverse partition members supported thereby inspaced relation to each other and to the ends of said frame and havingalined apertures throughout, a pair of upwardly extending arms securedto said frame rearwardly of said first member, a support connecting saidarms and having an aperture therethrough, an engine supported by saidframe forwardly of said second member and including a crank shaft, adifferential gear unit supported between said members and including apair of wheels and a propeller shaft, power transmission means supportedby both or said members and connected to said propeller shaft andincluding a or1ve shaft extending forwardly of said second member andabove said crank shaft, a belted connection between said crank and driveshafts and belt tightening means carried by said second member andincluding an operator control to render said means effective andineifective, said means comprising a member rotatably mounted in theapertures of said partition members, a crank rotatably mounted in theaperture in said support, and a universal connection between saio crankand said rotatable member.

2. A two wheeled tractor comprising a frame, first and secondlongitudinally spaced, transverse partition members supported thereby inspaced relation to each other and to the ends of said frame and havingalined apertures throughout, a pair of upwardly extending arms securedto said frame rearwardly of said first member, a support connecting saidarms and having an aperture therethrough, an engine supported by saidframe forwardly of said second member and including a crankshaft, adifferential gear unit supported between said members and including apair of wheels and a propeller shaft, power transmission means supportedby both of said members and connected to said propeller shaft andincluding a drive shaft extending forwardly of said second member andabove said crankshaft, and means to connect said crank and. driveshafts, said means including an operator control mounted in theapertures of said parti tion members and said support.

3. A two wheeled tractor comprising a frame, first and secondlongitudinally spaced, transverse partition members supported thereby inspaced relation to each other and to' the ends of said frame, a pair ofupwardly extending arms secured to said frame rearwardly of said firstmember, a support connecting said arms, an engine supported by saidframe forwardly of said second member and including a crankshaft, adifferential gear unit supported between said members and including apair of wheels and a propeller shaft, power transmission means supportedby both of said members and connected to said propeller and including adrive shaft extending forwardly of said second member and above saidcrankshaft, a driven shaft extending rearwardly of said first member andabove said propeller shaft, means carried by said second member toconnect said drive and crankshafts, a control for said means extendingrearwardly of said frame and supported in part by said support, andmeans carried by said first member interconnecting said driven andprope1 ler shafts.

4. A two wheeled tractor comprising a frame, first and secondlongitudinally spaced, transverse partition members supported thereby inspaced relation to each other and to the ends of said frame, a pair ofupwardly extending arms secured to said frame rearwardly of said firstmember, an engine supported by said frame forwardly of said secondmember and including a crankshaft, a differential gear unit supportedbetween said members and including a pair of wheels and a propellershaft, power transmission means supported by both of said members andincluding a drive shaft extending forwardly of said second member andabove said crankshaft and a driven shaft extending rearwardly of saidfirst member and above said propeller shaft, means carried by saidsecond member to connect said drive and crankshafts, and means carriedby said first member interconnecting said driven and propeller shafts.

ARTHUR S. LEIGI-ITON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

